Sushi Ranking Methodology
Blue Ocean originated a comprehensive seafood analysis and ranking methodology with our Guide to Ocean Friendly Seafood, an approach quickly adopted by other marine organizations. Our quantitative approach looks at a number of criteria, depending on whether the fish is wild-caught or farm-raised.
For wild-caught fish, the core points that are considered are:
1. Life history, including how fast the fish grows and how quickly they reproduce.
2. Abundance compared to natural or un-fished levels.
3. Habitat quality and gear impacts - does the catch method damage the habitat for fish that are left behind?
4. Management - are there regulations in place that effectively protect the fish and their ecosystem?
5. Bycatch - are other fish or wildlife accidentally caught when fishing for the target species?
For farmed fish, the core points considered are:
1. Inherent operational risks - this section looks at the layout of the farming system—can waste and fish freely move from the farm to the surrounding environment?
2. Feed examines the diet of the farmed fish, with a particular focus on the reliance of wild-caught seafoods to supply fishmeal and oil.
3. Pollution - is the water being discharged from the farm enclosure treated to minimize impact to the surrounding habitat?
4. Risk to other species considers whether the farmed species is able to escape and have a negative impact on the local environment (e.g. competing for food).
5. Ecological Effects, considers the ecological sensitivity of the area surrounding the fish farm.
For each seafood species, scientific and governmental publications are examined to obtain the necessary information to answer the five core points. Each core point has 8 additional questions, or “points of adjustment,” that help refine the ranking and generate a report. All reports are peer-reviewed for scientific accuracy and then displayed online for public viewing. For a full list of the point values that can be assigned and a description of each point of adjustment, please see the following documents:
Wild-caught fish
Farmed fish
Point values are averaged to determine the final ranking for each seafood species. Scores range from 0 to 4, which are then used to generate a “fish color”.
Final Score
2.60 - 4.00 Green
2.20 - 2.59 Light Green
1.80 - 2.19 Yellow
1.40 - 1.79 Orange
0.00 - 1.39 Red
Please contact seafood@blueocean.org with any questions related to the ranking process.
